Overview
- Girls know more words than boys
Eriksson et al, 2012; Frank et al, 2016 - First-born children know more words than later-born children
Goldfield & Reznick, 1990 - Children from higher SES families know words
Fernald, Marchman, & Weisleder, 2013
- Children from higher SES families receive more language input
Hart & Risley, 1995
- Vocabulary at 25 months predicts cognitive and linguistic abilities at 8 years
Marchman & Fernald, 2008
Do individual words carry demographic signal?
Data
Data
- Sex
- Assigned female at birth
- Assigned male at birth
- Birth order
- First-born
- Second-born
- Third-born or later-born
- Maternal education
- Below Secondary
- Secondary (~high school degree)
- College and Above (~college degree)
Data
Data
Data
Analysis
For a language and demographic:
produces ~ age + birth_order + (age + birth_order | item)
- fixed effect for each demographic in each language
- random effect for each item for each demographic in each language
- coding scheme gives difference between adjacent levels
Results
Results
Results
Results
Results
Results
Results
Results
Results
Results
Sex
Results
Birth order
Results
Maternal education
Takeaways
- Individual words are learned differentially by sex, birth order, maternal education
- Avoid bias in test design by excluding demographically-linked items
- Demographic differences in vocabulary size emerge from both quantity of speech and specific content differences
Part of larger work on variability and consistency in language learning
langcog.github.io/wordbank-book
All data and code available at
github.com/langcog/wordbank-book
